In general, the corium is a part between an outer skin and a subcutaneous tissue of in the skin of the vertebrate animal, occurs from a mesoderm, and is a fiber connective tissue having a thickness of 0.3 to 2.4 mm. The corium includes sweat glands, hair follicles, fat lines and the like, and most of the physiological function of the skin occurs here.
A characteristic symptom of the skin aging is an occurrence of wrinkles in the skin. The wrinkles occur due to a situation in which the corium gets thinner and the elasticity is lost by the gradual regression of the extracellular matrix of the corium, thereby bending the outer skin over the corium. When medically explained, an amount of hyaluronic acid (HA) decreases on the corium layer with the aging of the skin, an elongation shape of fibroblast is collapsed due to a decrease in mechanical tension caused by fragmentation of a collagen lattice network. Thus, a decrease in production of collagen and regression progress and the corium is aged, with the result that the wrinkles occur in the upper skins.
In order to remove the wrinkles formed on the outer skin, an surgical operation for pulling and cutting the skin that has lost its elasticity, and an invasive method such as a chemical decortication for by making minutely damage to the outer skin to ensure that the skin is reproduced are also used. However, the invasive method has a disadvantage of having many side effects.
Meanwhile, there are non-invasive methods such as a Botox injection method for paralyzing the muscle for a certain period of time to prevent the occurrence of wrinkles, and a method for injecting a filler to the corium lower layer. In the case of Botox injection method, there is a disadvantage of a temporary effect (5 to 6 months). Although the Botox may prevent the wrinkles generated by the folded skin due to the movement of muscle by preventing the movement of the muscle, there are limitations that cannot solve the wrinkles that have already occurred even when the skin loses the elasticity and there is no contraction of muscle. Because it is practically impossible to correctly inject a uniform amount of filler into the corium layer just below the wrinkles, and an uneven irregular surface is made, it is hard to perform the method of injecting the filler into the corium layer. Further, because the filler is also absorbed after six to nine months, there is a disadvantage of a temporary effect.
Korean Patent Application No. 10-2012-0013271 A entitled “syringe for corium regeneration and treatment methods” is the applicant of the inventors of the present invention that discloses a syringe that injects a gas such as carbon dioxide into the corium layer of the wrinkled skin to apply a minute separation damage to the site of the corium layer, while the gas is widely diffused to the site, and injects a liquid such as hyaluronic acid or collagen solution diluted with water into the separation space formed accordingly.
When alternately injecting the gas and liquid into the corium layer or the corium lower layer of the skin in this way, the blood flow of the capillary of the corium layer increases, the active switching of the collagenous tissue is induced, new collagen is produced on the corium layer of the wide site, and the dense arrangement of fibers is formed. Thus, wrinkles of the upper outer skin are lost or get thinner. This method has no side effect, and has an advantage that the effect of the wrinkle removal is maintained for a long period of time.
Furthermore, as a result of the previous researches, it was checked that this treatment method has an excellent effect capable of easily curing the depression wounds of various forms such as laceration sink scar, chickenpox scar, pimple scar and nail mark which could not be solved by any existing surgical techniques such as fractional laser, decortication, chemical peeling and scar removal as well as wrinkle care.
However, in such a syringe, there was also a problem of a presence of a dead space in which liquid always remains at a location where a cylinder bottom and a syringe needle are coupled to each other. That is, because a check valve is provided in the cylinder of the syringe, liquid is always accumulated between the upper end of the needle and the check valve, and the gas cannot be introduced first.
Accordingly, even when the gas is injected into the syringe filed with liquid at the time of the initial production through the check valve, the liquid is always present in the dead space from the lower end of the check valve to the syringe needle. Accordingly, at the beginning of pushing of the piston after the invasion, there was a problem that some liquid is injected rather than the gas being injected into the corium, thereby failing to perform a perfect treatment effect.
Thus, there was an urgent need for injecting only the gas into the skin from the initial pressurization of the piston by suppressing dead space to a minimum.
Matters described as the background art are merely intended to facilitate the understanding of the background of the present invention, and should not be recognized as corresponding to the prior art that has been already known to those skilled in the art.